clean up ActiveWorkoutSession

WorkoutsPlus/Features/Exercise/ExerciseUnit.swift

@@ -9,20 +9,23 @@ import Foundation
 import SwiftData
 
 @Model
-final class ExerciseUnit: Unit {
-		var name: String
-		var symbol: String
+final class ExerciseUnit: Unit, Identifiable {
+		@Attribute(.unique) var name: String
+		@Attribute(.unique) var symbol: String
 		
-		init(name: String, symbol: String) {
+		@Relationship(deleteRule: .cascade, inverse: \Exercise.unit)
+		var exercises = [Exercise]()
+		
+		init(_ name: String, symbol: String) {
 				self.name = name
 				self.symbol = symbol
 		}
 }
 
-extension ExerciseUnit: Identifiable {
+extension ExerciseUnit {
 		static let getUnits = [
-				ExerciseUnit(name: "Kilograms", symbol: "kg"),
-				ExerciseUnit(name: "Kilometers", symbol: "km"),
-				ExerciseUnit(name: "Meters", symbol: "m"),
+				ExerciseUnit("Kilograms", symbol: "kg"),
+				ExerciseUnit("Kilometers", symbol: "km"),
+				ExerciseUnit("Meters", symbol: "m"),
 		]
 }